Electrical components (e.g., fine pitch connectors) are commonly produced from thermotropic liquid crystalline polymers (“LCPs”). One benefit of such polymers is that they can exhibit a relatively high “flow”, which refers to the ability of the polymer when heated under shear to uniformly fill complex parts at fast rates without excessive flashing or other detrimental processing issues. In addition to enabling complex part geometries, high polymer flow can also enhance the ultimate performance of the molded component. Most-notably, parts generated from well-flowing polymers generally display improved dimensional stability owing to the lower molded-in stress, which makes the component more amenable to downstream thermal processes that can be negatively impacted from warpage and other polymer stress relaxation processes that occur in less well-molded materials.
Despite their relatively high flow capacity, current commercial LCPs still fall short of what is needed to meet the increased molding demands of intricate part designs without significant compromises to the final product performance. In this regard, various attempts have been made to improve the flow properties of conventional properties by lowering its melt viscosity. One approach to a lower melt viscosity has involved reducing the molecular weight of the polymer. However in general, decreased molecular weight polymers display reduced thermal and mechanical properties as well as poorer blister performance during lead-free soldering and other fabrication processes. Other approaches have also been employed that involve the addition of certain compounds to the polymer during compounding. For example, one approach employs the use of an oligomeric additive that may have carboxyl and hydroxy terminal groups. Such additives, however, particularly when used in relatively high amounts, can result in the formation of volatile products due to their decomposition during melt processing and/or use. This may, in turn, lead to the formation of blisters that can adversely impact the thermal and mechanical properties of the polymer and thus limit its use in certain applications.
As such, a need continues to exist for high flow liquid thermotropic crystalline polymers with excellent thermo-mechanical properties.